* The lack of foreign policy credentials on the Republican side is a historical aberration for a party that has traditionally gravitated toward candidates whose primary credentials relate to America’s role abroad. (The two with some experience this year: Jon Huntsman, the former governor of Utah and the current China ambassador; and John Bolton, the former United Nations ambassador. Neither has said for sure he is running.)

* While the economy is improving slowly, many economists predict that unemployment is likely to still be above 8 percent by the time Election Day rolls around. Asking to be returned to the White House because things could have been worse is a tough message to sell, as the 2010 midterm elections showed.

* Arguments over the debt and the deficit look deadlocked and politically dangerous, at least in the near term. Already, Democrats are split as to whether voters will reward or punish politicians for confronting Social Security and Medicare directly. Meanwhile, most Republicans have refused to even entertain the idea of raising revenue, otherwise known as taxes. Mr. Obama is likely to be caught in the middle of that issue.